Radial filtering 3D data

David C. Henley

3D seismic data present a challenge for processors attempting to attenuate coherent noise, because the spatial sampling of coherent noise wavefronts by 3D field geometry is non-uniform. This means that attenuation processes which rely on regular sampling, like f-k domain techniques, require the data to be interpolated prior to filtering. One method which does not require regularization of the data before application is radial trace filtering. Since this method is based on an interpolated mapping of the original data traces to the radial trace domain, the source-receiver offset values of the original traces need not be regular. It has been found that receiver line gathers provide the best sampling of coherent noise, and therefore provide the best domain for attenuating this noise. A simple trace header preparation step is required to ready such gathers for radial filtering. A ProMAX module, rad3d, has been written to do the required trace header preparation and is demonstrated in this report.